When Does Bilingualism Help or Hurt?

Parents are often asking what they can do to prepare their children for the increasingly globally-connected world. Often that answer has involved encouraging children to learn a second language or, for immigrant families, ensuring they pass on their native language to their children. Bilingualism (being fluent in two languages) not only allows people to communicate with others who speak those languages, but also to better understand different cultures and different ways of thinking. As such, there is no shortage of programs, language immersion schools, online materials, and other options being marketed to parents to encourage their children to become fluent in a second language.

While many of us share the intuition that learning two languages is better, or believe we’ve been told that from the media or scientific studies, the actual evidence is mixed. Dr. Ellen Bialystok, a professor of psychology at York University, has been studying the pros and cons of bilingualism for almost 40 years. She and her team have found evidence on both sides of the bilingualism argument. They find that children who regularly speak more than one language (bilinguals), on average, have slight linguistic disadvantages but also cognitive advantages as compared to children who speak only one language (monolinguals).

One of the findings from these studies was that bilinguals have minor disadvantages relative to monolinguals with regard to vocabulary. While the size of an individual’s vocabulary or lexicon varied widely, on average monolinguals had more vocabulary in their one language than bilinguals had in either of their languages alone. Also, the time (in milliseconds) it took to retrieve words when thinking was slightly longer for bilinguals. So, that feeling you get when you’re trying to think of a word and it’s just not coming to you—that’s the experience that bilinguals have more often. These slight disadvantages of bilingualism may be due to having to resolve the cognitive conflict of choosing the word from the appropriate language, rather than simply choosing the appropriate word, as monolinguals do.

However, the effort the brain has to put into the management of this “joint activation” of both languages leads to the cognitive advantages observed for bilinguals over monolinguals. Bilinguals have, on average, stronger executive control, meaning they have enhanced cognitive abilities in areas that have nothing to do with linguistics, but rather overall management of cognitive functions. This enhanced executive control boosts bilinguals’ capability in areas such as working memory, inhibitory control, cognitive flexibility, and multitasking. In particular, bilinguals are especially good at tasks that involve monitoring conflict, a skill one practices a lot if trying to use words from one lexicon while avoiding those from another.

To understand why these enhancements to the bilingual brain occur, it’s helpful to know about neuroplasticity. Neuroplasticity describes how our brains change across our lives. Connections between brain cells strengthen and weaken as we reorganize information, as we learn, and as we get older. Neuroplasticity is why patients with brain injuries are often able to at least partially recover , and why people with a deficit in one physiological sense (poor eyesight, for example) can sometimes develop a greater capacity in another one of their senses (i.e. better hearing). The executive control center of the brain is the primary area responsible for managing dual languages and resolving conflicts. As bilingual children learn and use multiple languages (appropriately monitoring and using words from the right language at the right time) they are exercising and strengthening their executive function via neuroplasticity.

So while bilingual children may have a slightly smaller vocabulary for each language as compared to their peers who speak only one language, they gain a cognitive advantage by having strengthened executive function. These findings appear to hold across ethnicity and socio-economic status. It’s important to note that these advantages were seen in fully bilingual children who use both languages regularly rather than occasionally. Also, the longer an individual is bilingual, the more cognitive benefit they get. While these benefits alone are encouraging, bilingual children may also benefit from Dr. Bialystok’s findings that suggest that bilinguals have a later onset (about 4 years on average) of dementia and Alzheimer’s disease in old age.

So while there are a host of advantages to the ‘bilingual brain’—executive control and memory benefits—applicable to a wide range of situations outside of the linguistic context and only a few minor disadvantages, it’s safe to say that bilingualism isn’t a cure-all for developing or maximizing all cognitive and linguistic skills. That said, it’s also safe to say that bilingualism has much to contribute to the developing brain. In addition to improvements in cognitive and language skills, bilingualism has many other advantages too, of course, like the ability to communicate and connect with more of the world’s population and the associated opportunities to travel. Thus, parents might consider not only the cognitive benefits but the social and experiential ones as well when deciding whether the immersion school or enrichment program makes sense for their children.

I find your article interesting. I have read previous articles about the benefits of being bilingual, and to use moi(me) as an example, I think you are correct on some.

For the record, my mom only knows spanish. She is illeterate. As a matter of fact, she put me in school, for spanish classes through kindergarden and so on. For my mom, it was important for her to make me understand spanish, after all, allshe knew was to speak spanish. And there I am. In kindergarten or third grade learning school in spanish. It was until 5th grade, where I had a teacher who wanted to teach us in english, because it would give us greater opportunity. I already knew english. After all, I was born in Chicago. But a teacher having his classes in english? My mother didn't complain. Not because I didn't learn in spanish, but because the man was a great teacher. And he was. He wasn't white. He was Colombian. And by far, I remember him til this day.

I admit I prefer speaking and writing in english, for social and personal reasons. I do know how to read and write in spanish. I mean, my mom doesn't know, english, so I need to speak to her in spanish. But my bilingual skills is not as fair as you might suggest. For example, is not the vocabulary, is the cultural. I know a word to say in english, but in spanish? Have no idea. Is not that my parents never taught me spanish, it is my long-lasting language since I was born. Is just that a culture like America, I managed to take advantage for it. Even my sisters: their children can speak only english. My mom gets upset at times, because she thinks my sisters are intentionally teaching them english, without remembering who they are and where they come from. Five of my seven sisters were born in Mexico, and the fact that those five children are monolinguals than bilingual does disappoint my mom. She's afraid that when she dies, her identity will be forgotten.

Of course being bilingual has many advantaes. Greater job opportunities and balance understanding, beimg bilingual is important. Especially in this day and age; in my community. You can get jobs and opportunity, all becausefor being bilingual. I can tell you from experience, I tookadvantage of that. I didn't call it cognitive abilities. I call it greater opportunities. And can you blame me? My spanish was not as good as my english, but the fact that I can read it or write, it arguably gave me more opportunities than speaking one sole language -- especially when it came to jobs. And politically speaking, many American companies are trying to court the Latino or Hispanic audience. We not only can get jobs, but we can decide elections. I'm smart enough to see as a win-win.

My spanish is good, but I'll be lying if its great. Some words I can say in english than spanish, and coming from a pretty spanish household, I literally cannot say some things in spanish so that my mom can understand. My dad knows english, he's fine. But my mom? I am her scribe. And english is not her repertoir. But lucky for me, I know spanish enough to tell her how much is her balance on her checking account. The lil things I'm quite aware off, and for the most part, she is up-to-date. But I prefer english. Why? I guess I can say I prefer American culture. I like english. I can read, write and communicate comfortably. Plus, is the number one reliable language in the world, ironically, behind spanish. So is more than a sae bet. But it is a survival tactic in some way.

I always considered myself extremely smart. The issues I dealt with was in english. But that's my choice. Many do like a mix, and prefer the music on an even heel. Me, on the other hand, is 100% english. I do like spanish music, especially Rock en Espanol. However, if I were bilingual, I would take advantage off it. I will omly use those skills as necessary, I admit. But when it comes to my true potential cognitive skills, no secret is english all the way. After all, I do come to PsychToday as an english speaker.